Machines having at least one rotating component are frequently used in a variety of situations, such as industry, farming, and construction. Such machinery is typically operated outdoors and often may be too large to be stored indoors during periods of nonuse. Machinery used outdoors is exposed to a wide variety of weather and environmental conditions such as precipitation, wind, dirt and temperature extremes. Due to the exposure in difficult conditions, continual lubrication of moving parts may be required to maintain the equipment in proper operating condition.
A self-propelled irrigation system used on a farm is an example of machinery which is subject to these concerns. Some self-propelled irrigation systems use chain drives for rotating the wheels which propel these systems. The chains, sprockets and other rotating drive elements of the propulsion power transmission are constantly exposed to the ambient environmental conditions and to water from the irrigation system. Without constantly reapplying lubricant to the chains, the lubricant is quickly washed off and the chains fail, disabling the whole irrigation system.
In these situations, lubrication is typically applied manually at intervals which, in many cases, are irregular. Significant time may be required to lubricate the moving parts of the irrigation systems, and to maintain the parts lubricated under the difficult conditions of constant exposure to water. Even the most thorough and repeated manual lubrication effort is sometimes inadequate to prevent failure of the chains. Similar problems exist with other types of equipment having moving parts which are exposed to constant difficult environmental and use conditions.
Attempts have been made to continuously lubricate machinery drive elements by placing the drive elements in a rigid enclosure and filling the enclosure with a reservoir of lubricant in contact with the drive elements. See, for example, U.S. Pat. No. 3,762,643, entitled "Irrigating Apparatus," illustrating a rigid enclosure surrounding a power transmission of a self-propelled irrigating apparatus. While such an arrangement accomplishes the purpose of continuous lubrication, such a lubrication system is typically an integral part of an entire irrigation apparatus and thus cannot be easily added to existing machinery. Furthermore, many types of machinery utilize extensive drive devices, such as large sprocket wheels or long drive chains, which could not be feasibly enclosed within a lubricant reservoir.
It is with regard to this background information that the improvements available from the present invention have evolved.